Influence of reduced graphene oxide–modified CF on mechanical properties and durability of cement-based composites

The performance of carbon fiber (CF)-reinforced cement-based composites is significantly limited by the weak interface characteristics between CF and the cement matrix. To address this issue, this study proposed an efficient interface enhancement method based on a high-performance nanomaterial, reduced graphene oxide (rGO). Graphene oxide (GO) was uniformly deposited onto the CF surface via electrophoretic deposition, followed by moderate reduction using L-ascorbic acid to prepare rGO-modified CF (rGO/CF). The results indicated that the addition of rGO/CF significantly improved the mechanical properties and durability of composite materials. When the volume fraction was 0.9%, the 28-day compressive and flexural strengths increased to 42.27 MPa and 9.57 MPa, respectively, representing improvements of 17.32% and 15.88% compared to unmodified CF. The water absorption rates decreased by 14.66% and 4.92% after 6 h and 7 d, respectively. Microscopic structural analysis revealed that the rGO on the CF surface exhibited a typical nano-core effect in the cement matrix. This effect promoted the directed deposition of hydration products, which preferentially formed on the fiber surface, filling the pores in the interfacial transition zone of CF/matrix and forming a locally dense structure. This study provides a new strategy for the efficient utilization of CF in cement-based materials.